Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information,
see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module,
and to see a list of the releases in which each feature is supported, see the feature information table.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature
Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Information About IPv6 Rapid Deployment

IPv6 Rapid Deployment Tunnels

The 6RD feature is an extension of the 6to4 feature. The 6RD feature allows a service provider (SP) to provide a unicast
IPv6 service to customers over its IPv4 network by using encapsulation of IPv6 in IPv4.

The main differences between 6RD and 6to4 tunneling are as follows:

6RD does not require addresses to have a 2002::/16 prefix; therefore, the prefix can be from the SP’s own address block.
This function allows the 6RD operational domain to be within the SP network. From the perspective of customer sites and the
general IPv6 internet connected to a 6RD-enabled SP network, the IPv6 service provided is equivalent to native IPv6.

All 32 bits of the IPv4 destination need not be carried in the IPv6 payload header. The IPv4 destination is obtained from
a combination of bits in the payload header and information on the router. Furthermore, the IPv4 address is not at a fixed
location in the IPv6 header as it is in 6to4.

The 6RD SP prefix was selected by the SP for the IPv6 deployment shown in the figure below. The 6RD delegated prefix is derived
from the SP prefix and the IPv4 address bits, and is used by the CE for hosts within its site.

Standards and RFCs

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use
these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products
and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

Feature Information for IPv6 Rapid Deployment

The following table provides release information about the feature or features described in this module. This table lists
only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise,
subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco
Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1. Feature Information for IPv6 Rapid Deployment

Feature Name

Releases

Feature Information

IP Tunneling: 6RD IPv6 Rapid Deployment

Cisco IOS XE Release 3.1S

The 6RD feature allows a service provider to provide a unicast IPv6 service to customers over its IPv4 network by using encapsulation
of IPv6 in IPv4.